Generation of C-point and L-line polarization singularities with a 3-pinhole diffraction setup

Abstract

We generate an inhomogeneous polarized field consisting of C-point and L-line polarization singularities with a 3-pinhole diffraction setup and a radially polarized light source. We characterized the polarization states of the field using the Stokes parameters which was acquired from the classical measurement method. We used the S₁ and S₂ parameters further to generate the Stokes field and Stokes phase to locate the C-points. The L-lines were identified and constructed based from the S₁ and S₂ parameters. We have observed that both types of polarization singularities form a hexagonal lattice. In the S₃ parameter, we observed that the L-lines serve as boundaries between right and left-handed polarization states. Moreover, we observed that the regions of right and left handed polarization states were enclosed within an upright and inverted triangle, respectively, formed by the L-lines. Recent studies suggest that focused polarization singularities can lead to generations of photonic skyrmions and higher order singularities.